An integrated starter alternator for the 42 V PowerNet

This paper concerns the modelling and implementing a prototype integrated starter alternator (ISA) employing an induction machine, for the potential use in the future 42 V PowerNet. The system includes a direct rotor flux oriented (DFOC) induction machine drive, which is operated in both motoring and generating modes (i.e. starter and alternator modes). During starting, the induction machine cranks the engine, which is emulated using permanent magnet DC motor, with high starting torque. In the generation mode, the power is input to the ISA from emulated engine while the DC bus voltage is maintained at 42 V. The model and prototype hardware successfully allow many operational aspects to be predicted, in particularly the regulated DC voltage developed by ISA during load dump and sudden speed change.